The landscape of today's telecommunications network is vastly different from that of just a few years ago. The volume of data transfer is fast superseding the volume of voice traffic. The switched voice-dominated networks will most likely be replaced by data-dominated networks. However, the change will not take place overnight. The transition from voice-switched to data-switched networking is an evolutionary process rather than a revolution. The transition involves migrating from one networking philosophy to a second.
Voice switching involves intelligence that resides in the telecommunications network itself, since the end-user equipment, i.e. the telephone, is a fairly simple device. In order to make networks more manageable, the needed intelligence has been moved into the Intelligent Network (IN) nodes.
In data networking, the network primarily provides transport of data while the intelligence resides in applications running on hosts connected to the data network. Of importance is the ability to provide faster transport while minimizing delay. As part of the transition, customers and user groups are now able to be connected with virtual connections by implementing virtual private networks (VPN). Further, the provisioning of different quality of service (QoS) levels is also important. In order to implement various QoS levels in an effective and manageable way, service management systems have been introduced.